JP2542003Y2 - Optical semiconductor device module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] The present invention relates to an optical semiconductor device module used for optical communication, optical measurement, and optical information processing.

To the WDM communication of [Prior Art] 2 wave has a light emitting modules that oscillates light of wavelength lambda _1, the light emitting modules that oscillates light of wavelength lambda _2, 1 pieces of optical fiber comprising a transmission line And two multiplexer / demultiplexers for selectively separating or merging light of wavelength λ ₁ and light of wavelength λ _2, a light receiving module for receiving light of wavelength λ ₁ , and a light receiving module for receiving light of wavelength γ ₂ Is necessary.

In order to reduce the error rate in communication, the multiplexer / demultiplexer needs to obtain near-end crosstalk of about -50 dB and far-end crosstalk of about -30 dB, and a wavelength filter made of a dielectric multilayer film. And a lens for collimating the light incident on the wavelength filter plate, which is expensive.

Therefore, recently, a configuration of a low-cost fiber fusion coupler and a light receiving module having a built-in wavelength filter may be used instead of the configuration of the multiplexer / demultiplexer and the light receiving module. Also, when using a laser diode as a light emitting device having a wavelength lambda _1, may be required wavelength filter built emitting modules attenuating the wavelength lambda ₂ of the component of the spontaneous emission component.

Here, a light receiving module having a built-in wavelength filter will be described as an optical semiconductor module.

Figure 2 is a sectional view of a conventional optical semiconductor modules for receiving the wavelength lambda ₁ for example, in FIG., (1) an optical fiber, (2) the wavelength filter plate made of a dielectric multi-film layer, (3 ) Is a lens, (4) is a cap, (5) is a glass plate, (6) is a photodiode, (7) is a stem,
(8) is a lead, (9) is a hermetic glass, and (10) is a housing.

The wavelength filter plate (2) is bonded with a transparent adhesive so that the surface of the dielectric multilayer film for preventing a change in characteristics due to humidity is directed to the optical fiber (1). The photodiode (6) is made by fusing the cap (4) and the glass (5) with a low-melting glass in order to prevent an increase in dark current due to humidity, and sealing the stem (7) and the lead (8) with glass for airtightness. Airtightness is obtained by fusing in (9) and welding the cap (4) and the stem (7). The optical fiber (1), the filter plate (2), the lens (3), the glass plate (5), and the photodiode (6) are such that light emitted from the core of the optical fiber (1) is incident on the light receiving surface of the photodiode. And fixed to the housing (10).

Next, the operation will be described. If the WDM communication, the light emitted from the optical fiber (1) include the wavelength lambda ₁ light and wavelength lambda ₂ of light. Light of the wavelength lambda ₂ is reflected by the wavelength filter plate (2), light of the wavelength lambda ₁ is transmitted through the wavelength filter plate (2). Next, the light of wavelength λ ₁ is converged by the lens (3), passes through the glass plate (5), is incident on the light receiving surface of the photodiode (6), is converted into electricity, and converts an electric signal from the lead (8). Output.

[Problems to be solved by the invention]

Since the conventional optical semiconductor device module is configured as described above, the surface of the dielectric multilayer film of the wavelength filter must be shielded from the humid air layer, and it is necessary to adhere with an adhesive. However, there is a problem that the bonding process is expensive and expensive.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an optical semiconductor device module that can shield a dielectric multilayer film surface of a wavelength filter from a humid air layer and does not require a bonding process. With the goal.

[Means for solving the problem]

The optical semiconductor device module according to the present invention is to produce a wavelength filter plate by depositing a dielectric multilayer film on the surface of the glass plate fused to the cap on the optical semiconductor device side, and to combine the optical semiconductor device with the above-mentioned cap and wavelength filter. It is an airtight structure with a board.

[Operation] In the optical semiconductor device module according to the present invention, the dielectric multilayer film surface is hermetically sealed by a gas such as nitrogen having a low humidity, so that a change in filter characteristics due to humidity is prevented.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a glass plate is fused to a cap (4) with low-melting glass, and then a dielectric multilayer film is deposited on the photodiode (6) side to produce a wavelength filter plate (2). In order to prevent the dark current from increasing due to the humidity of the photodiode (6), and to prevent the characteristics of the wavelength filter plate (2) from changing due to the humidity, the cap (4) and the stem (4) are placed in a low humidity gas atmosphere such as nitrogen. 7) is welded to form an airtight structure.

Next, the operation will be described. If the WDM communication, the light emitted from the optical fiber (1) include the wavelength lambda ₁ light and wavelength lambda ₂ of light. Is reflected by the wavelength filter after being focused (2) with light having a wavelength lambda ₂ emitted from optical fiber (1) is a lens (3). The light of the wavelength lambda ₁ emitted from optical fiber (1) is focused by the lens (3), after having passed through the wavelength filter (2) is converted to an electrical incident to the light receiving surface of the photodiode (6),
An electric signal is output from the lead (8).

In the above embodiment, a photodiode is provided as an optical semiconductor element. However, the optical semiconductor element may be an optical semiconductor integrated circuit having an avalanche photodiode or a light receiving element.

In the above embodiment, the case of the light receiving module has been described. However, the light emitting module may be used, and the optical semiconductor element may be an optical semiconductor integrated circuit having a laser diode, a surface light emitting diode, an edge light emitting diode, or a light receiving element.
The same effects as in the above embodiment can be obtained.

Further, in the above-described embodiment, the case where the optical fiber is provided is described. However, the optical semiconductor element module may be provided with a receptacle to which the optical fiber connector can be attached, and the same effects as in the above-described embodiment can be obtained.

[Effect of the invention]

As described above, according to the present invention, the cap, the stem,
A light transmitting plate and a wavelength filter plate formed by vapor-depositing a dielectric multilayer film on a surface of the light transmitting plate facing the optical semiconductor element are provided in one hermetic structure formed of a gas such as nitrogen having a low humidity. Thus, it is possible to prevent the characteristic change of the wavelength filter plate due to humidity, and it is possible to obtain an inexpensive optical semiconductor element module without having to bond the dielectric multilayer film surface with an adhesive unlike the related art.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing an optical semiconductor module according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional optical semiconductor element module. (1) is an optical fiber, (2) is a wavelength filter plate, (3)
Is a lens, (4) is a cap, (5) is a glass plate,
(6) is a photodiode, (7) is a stem, (8) is a lead, (9) is an airtight glass, and (10) is a housing. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Scope of request for utility model registration] 1. An optical semiconductor device module comprising: an optical semiconductor device attached to a stem; and a cap attached to the stem and having a light transmitting plate at a position facing the optical semiconductor device. A stem, the light transmitting plate and one hermetic structure formed of a gas such as nitrogen having a low humidity, and a wavelength filter formed by depositing a dielectric multilayer film on a surface of the light transmitting plate facing the optical semiconductor element. An optical semiconductor element module, comprising: a plate;